Written by Xixi Richards, Peer Reviewed by Xiaochen Liu , Edited by Courtney Coleman
Overview
Mosquitos are often vectors of disease, with dengue fever being one of them. Upon infection, the virus will infect a skin cell and take it over, where it will then control the cell. After this, the virus can spread by replicating its RNA and repeating this process among other cells (1). Dengue is actually four related viruses, and people can become infected with dengue up to four separate times. Because of this, the dengue virus infects about 400 million people a year, with 100 million people becoming sick, and 40,000 dying from severe dengue (2).
Transmission and Symptoms
As previously stated, mosquitos are the main vectors of dengue fever, with Aedes aegypti and Aedes albopictus being the most common species (3). Dengue is most commonly found in tropical and subtropical urban and semi-urban areas. This makes about 4 billion people live in an area at risk of infection. Dengue can also be transmitted in utero, where a pregnant mother can infect her child during pregnancy or childbirth. Additionally, there has been one case of breast milk spreading dengue from mother to child (2). While dengue fever infects about 400 million people yearly, about 80% of these infected people are asymptomatic (3). The other 20% mainly experience acute flu-like symptoms, including nausea, vomiting, rash, aches, and eye pains, which resolve after about a week; however, there can be more severe cases, known as severe dengue (3). In the case of severe dengue, symptoms including belly pain, vomiting, bleeding from the nose or gums, and vomiting blood or blood in the stool, normally occur a day or two after a fever has subsided (2). Figure 1 shows the total dengue cases per year from 2010-2022, as well as the proportion of cases with severe dengue and the fatality rate.
Fig. 1 Source: Data entered into the Health Information Platform for The Americas
(PLISA, PAHO / WHO) by the Ministries and Institutes of Health of the countries and territories of the Region. Available at: https://www.paho.org/plisa
Treatment and Prevention
There is currently no vaccine available for people who have not been previously infected with dengue fever; however, there is a vaccine, Dengvaxia, available to children ages 9-16 who have previously been infected, to protect from other dengue viruses. There is no treatment to treat the dengue virus, specifically; however, medicines can be given for symptom relief. For those who are infected with mild symptoms, treatment includes rest, fluids, and acetaminophen or paracetamol, to help reduce fever and general pain. For
those with severe dengue, it is recommended to go to the nearest hospital or emergency room, since this can be life-threatening. Due to mosquitos being the vector of dengue, the best possible way to avoid infection is by preventing mosquito bites. This includes personal protection and preventing mosquitoes from breeding (3). Personal protection includes wearing clothes that cover the skin, installing home window screens, and using repellent. In order to prevent the breeding of mosquitoes, one can minimize pools of still water, as these are perfect breeding grounds, cover and empty water storage containers on a weekly basis, and use insecticides on outdoor water storage.
References
1. “Dengue Viruses.” Scitable by Nature Education, 2014,
https://www.nature.com/scitable/topicpage/dengue-viruses-22400925/.
2. “Dengue.” Centers for Disease Control and Prevention, 09 February 2023, https://www.cdc.gov/dengue/index.html.
3. “Dengue and Severe Dengue.” World Health Organization, 10 January 2022, https://www.who.int/news-room/fact-sheets/detail/dengue-and-severe-dengue
4. “Dengue Fever.” Mayo Clinic, 05 October 2022,
https://www.mayoclinic.org/diseases-conditions/dengue-fever/symptoms-causes/syc-203 53078
This post is not a substitute for professional advice. If you believe that you may be experiencing a medical emergency, please contact your primary care physician, or go to the nearest Emergency Room. Results from ongoing research is constantly evolving. This post contains information that was last updated on April 13,2023.
Xixi Richards is currently a Microbial Biology and Music major undergraduate at UC Berkeley.
Xiaochen Liu is a 5th year Ph.D. student in Epidemiology focusing on the genomic risk factor in Alcoholic-associated Hepatitis at UC Irvine.
Courtney Coleman is a master's degree candidate in biology at Harvard and Co-President of Students vs Pandemics.